Mechanical shift register



July 28, 1959 HUNTER 2,896,843

MECHANICAL SHIFT REGISTER Filed Aug. 23, 1957 IN V EN TOR.

Joflafh 0/7 H un fer United States Patent MECHANICAL SHIFT REGISTER Jonathan Hunter, Berkeley, Calif., assiguor to Marchant Research, Inc., a corporation of California Application August 23, 1957, Serial No. 679,818

11 Claims. (Cl. 235-61) The invention relates to a mechanical shift register for serially reading out and/or visually displaying a value which has been generated previously in a computer or the like.

The register comprises a plurality of ordinally arranged numeralwheels with an interordinal member being provided for each numeral wheel. The lowest ordinal numeral wheel is set in accordance with a predetermined, or sensed, ordinal value standing in the computer. The adjacent interordinal member is then set to a corresponding value under the control of the lowest order numeral wheel after which the second numeral wheel is set to this corresponding value under the control of the interordinal member. At the same time that the second numeral wheel is set to such value, the first ordinal numeral wheel is set to a new value corresponding to the second ordinally sensed value. This serial read-out process is repeated until a multi-order value has been transferred from the computer to the shift register.

The numeral wheels and interordinal members are mounted upon a common drive shaft and are frictionally engaged by the drive shaft. The numeral wheels and interordinal members are alternately locked and released in respective groups. Upon release, the numeral wheels are each frictionally driven to the extent permitted by the respective values standing in their adjacent interordinal members. Then the numeral wheels are locked and the interordinal members are released at which time the interordinal members are frictionally driven to the extent permitted by the values standing in their respective adjacent numeral wheels.

In the embodiment described, the values are serially entered from right to left; however, the values could as well be introduced in the reverse direction.

The means for entering the ordinal values, one by one, may be controlled either by a keyboard, or by another register. The invention is not directed to the specific manner in which values are entered into the first order, but is only concerned with the manner of transferring the successive ordinal values from one numeral wheel to the next. Therefore, an entry mechanism is provided which is shown in schematic form only for manually setting the lowest ordinal numeral wheel of the register in accordance with successive values which are to be displayed.

An object of the invention is to sequentially enter and ordinally propagate values in a numeral wheel register.

Another object is to provide a shift register of this type which is simple in construction and precise in operation.

A further object of the invention is to provide a registering mechanism which will receive and propagate the successive character indications at a high rate of speed.

A further object of the invention is to provide a serial read-out registering mechanism which is unlimited as to the number of denominational orders contained therein.

Another object is to provide a combination of components which aligns and locks numeral wheels of a serial read-out register in positions of full digital display.

A further object is to eliminate the precession normal- ICC 1y incident to angularly setting adjacent components one upon the other in succession.

A further object is to set a first displaying register member to a selected value indicative position, to thereafter set a non-displaying member to a corresponding equivalent position and to thereafter set a second displaying register member to the original selected value indicative position.

An additional object is to provide a mechanical shift register which operates to serially generate electric pulses indicative of the displayed value.

A further object is to provide a shift register which is adaptable to accommodate multi-order values of any common radix system.

In order that the invention may be practiced by others it will be described in terms of an express embodiment, given by way of example only, and with reference to the accompanying drawing in which:

Figure 1 is an exploded isometric view of an entire me chanical shift register.

Figure 2 is a plan view showing the relationship between the assembled numeral wheel and interordinal member, and their respective locking cam lobes.

Figure 3 is a plan view showing details of the manually set value selecting mechanism.

General description The mechanism of the invention propagates single manually selected digits from order to order, and may be used as an operand type register. However, it may also be used made in ascending numerical order.

to display digits which are serially read-out from an electronic memory system, or alternatively, may be used in conjunction with an arithmetic unit to display the results of a calculation as the figures of the results value are serially developed. The primary concern of the invention is to disclose a mechanical, serial, read-out register, which may be used in any one of the suggested manners.

An exploded view of the invention is shown in Fig. 1. In this drawing is shown a cyclic clutch 11, a locking cam shaft 13, and a drive shaft 15. The clutch 11 is of the type shown in U.S. Patent No. 2,383,731, issued August 28, 1945, and bearing the reference numeral 362 in Fig. 30 of the patent. Clutch 11 normally is engaged only for a single cycle and causes the register to execute a single cycle of operation. A multi-cyclic clutch would necessarily be used in place of the single cyclic clutch if the register is to be operated continuously to display digits readout consecutively from a computer. Depression of key 19 closes the motor switch contacts 23 in known manner whereupon an electric motor (not shown) rotates the drive shaft 17. Meanwhile, depression of key 19 engages the clutch 11 which drives a jackshaft 21 for a single revolution. A spur gear 25 is fixed on shaft 21, and is driven 360 in a counterclockwise direction for each engagement of the clutch. In mesh with gear 25 at a 1:1 gear ratio is a spur gear 27. In mesh with spur gear 27 is a smaller spur gear 29. The gear ratio between spur gear 27 and the smaller spur gear 29 may range upward from a lower limit of 2:1 to approximately 3:1. Spur gear 27 is integral with the locking cam shaft 13, and spur gear 29 is integral with the numeral wheel drive shaft 15.

A digital selection is manually made by means of a dial 31. The dial is integral with a ratchet 33 and a detent 35 is urged by spring 37 to engage said ratchet. The dial may be manually rotated by finger piece 39 only in a clockwise direction; thus, the digital selections are always Connected to the dial 31 is a spur gear 41 and in mesh with spur gear 41 at a 1:1 gear ratio, is a wide gear 43 of a selector unit gen erally indicated at 45. The selector unit is mounted to rotate freely about drive shaft 15. The selector unit 45 carries a value selecting projection 47, (Figs. 1 and 3) which is set in one often selected positions in accordance with the decimal selection made at dial 31. The projection 47 lies. in the plane of rotation of a lug 51-1 carried by the first order numeral wheel 50-1.

The next consecutive higher order numeral wheel is numbered 50-2, the suffix 2indicating.that it is the second order numeral wheel. The interordinal member 60-1 is set under the control of the numeral wheel 50-1 and bears the same suffix of 1.

Each numeral wheel and each interordinal member is fitted over an individual spring loaded ball 71 carried by drive shaft 15. Each spring-loaded ball 71 lies in a recess 73 drilled in the drive shaft. The inner circumfen ence 58 of each numeral wheel 50 and the inner circumference 68 of each interordinal member 60 is thus continually engaged by a respective spring loaded ball 71 andin-this. manner is.frictionally coupled to rotate in the direction of rotation of the drive shaft. The frictional coupling between the shaft 15 and. each numeral wheel and, each interordinal member is, however, easily broken by merely holding one or more of the components against rotation. The components may be held in this manner without impeding rotation of the drive shaft.

Each numeral wheel carries a contact lug 51. and a sto lug 52, Each interordinal member 60 carries a contact lug 6;1,and a stop lug 62. Projection 47 acts as a stop for the contact lug 51-1 of the numeral wheel 50-1. The stop lug 52-1 of numeral wheel 50-1 cooperates with the coplanar contact lug 61-1 on the interordinal member 60-1. In Fig. 2, the stop lug 52-1 is more clearly shown on the inner circumference of the first order numeral wheel 50-1. In this drawing the components are shown in. assembled position and the contact lug 61-1- of the first interordinal member is shown in true relation to the stop lug 52-1. Also. shown is the stop lug 62-1 of the interordinal member 6.0-1. Lug 62-1 cooperates with the coplanar contactlug 51-2 of the secondhighest order numeral wheel 50-2.

First the interordinal members are locked in their respective angular positions and the register numeral wheels are released and angularlyv advanced by the main drive shaft 15 until the contact lug 51 on each numeral wheel abuts a respective coplanar stop lug 62 of the adjacent lower interordinal member. Then the numeral wheels are locked and theinterordinal members 60 are frictionally driven until their respective contact lugs 61 each abut an angularly set stop lug 52 of the respective numeral wheels. In this manner a selected value is propagated from the lowest order through successive higher orders.

The locking cam shaft 13 is mounted for rotation directly below the drive shaft 15 and is rotated 360 during each clutch cycle, whereas the drive shaft 15 is rotated twice during each clutch cycle.

The locking cam shaft 13 carries two opposed banks of Geneva type camlobes 80 and 82 along its length. Each cam lobe covers approximately 180 of the cam shaft circumference. During approximately half of a cam shaft revolution each numeral wheel 50 is locked against angular movement by a respective carn lobe 80 and during the second half revolution of shaft 13, the interordinal members are locked against angular rotation by respective cam lobes 82.

Each numeral wheel and interordinal member has ten distinct Geneva lock surfaces or concave depressions 54 and 64, respectively, spaced around its respective circumference. These depressions are engaged by the respective mating Geneva cam lobes 80 and 82 to lock the numeral wheel or member in one of ten' possible angular positions. These positions, of course, correspond to the ten decimal digits as displayed by the shell of the numeral wheel.-

The invention is not limited to the decimal system, but could as well be made to read out and display values in any common number system. The invention would read out such values by simply altering the components so that each had the number of depressionsequal to the radix,

of the number system used. For example, eight depressions would be employed to read out octal values, and the manual input dial 31 would be correspondingly changed to contain only eight possible positions.

An additional advantage of the invention is that with any radix system selected, an additional place may be included as the radix point, and propagated in proper re1ationship with the digits ofthe value. For example, in the embodiment shown an additional depression is formed on the componentsand theeleventh depression would indicate the decimal point. The dial 31 would be altered correspondingly and by selecting the decimal point at the dial, the point would be propagated in the selected relation to the other decimal figures selected.

To further illustrate the invention, propagation of a two digit number willnow be described. A selection of 3 is manually made at dial 31 which acts through the gears 41 and 43 to set the value selecting projection 47 at the angular position which is indicative of the value 3. The value selecting projection 47 projects leftward into the plane of the contact lug- 51-1 on the numeral wheel50-1. Following such digital selection, the operation initiating key 19 is depressed, and the clutch 11 is engaged for a single cycle.

In the initial position of theparts, the trailing ends of the cam' lobes 80.are standing in locking relation with a portion. of theirmating camsurfaces 54 on the numeral wheels. Then whenthe clutch is engaged the numeral wheels, are. released from cam lobes and the interordinal'memberst are lockedby cam lobes 82. The first wheel 50-1. is driven until its contact lug 51-1 abuts the projection 47 and the numeral wheel is thereby set to the angular position, indicative of the value 3. The cam lobes 82' thereafter release the interordinal members and lobes 80 engage all of the numeral wheels. This permits all interordinalmembers 60 to rotate to value representing positions.- determined by their adjacent numeral wheels. The cycle ends with the numeral wheels locked by lobes 80 in full display position with the 3 displayed inthe first order. I

A valve of ;7 is now selectedat dial 31. The second cycle is initiated as before, by operation of key 19. In the first half of this secondcycle the 3 selection is propagated to be displayed by the second order numeral wheel 50 2;; and ;-the 7 is placed in the first order numeral wheel 50-1.

During the, first half of this second cycle the first order numeral wheel 50-1 advances until it abuts the projection 47 which now indicates the 7, and the numeral wheel 50-2 advances until its contact lug 51-2 abuts the stop-lug 62-1 of the interordinal member which stands at avalue .of3. Simultaneously, the interordinal member 60-2 is driven until its contact lug 61-2 abuts the stoplug 52-2 on thesecondhighest numeral wheel 50-2 which stands. at a value of 3. As the second cycle reachescompletionthe numeral wheels stand locked in theirfull display positionsby respective cam lobes 80 and the decimal value3 7 is displayed by the register. The gperation may of course be repeated to enter succeeding igits.

It will be .noted that if no .new selection were made in this second cycle, i.e., if the decimal 3 were to remain as the s election in the second cycle, then the first order numeral wheel would beheld against rotation by the existing contact of stop lug 51-1 with the projection 47. That is, the projection 47 would remain in the selected demical 3 position and prevent the numeral wheel 50-1, from moving. to .a new selected position after release by its cam 1obe80.- Therefore, the projection 47 is removed momentarily from the, path of the stop lug 51-1 at the beginning of. each operating cycle. For this purpose there is provided a cross arm pivotally mounted at each of its ends 92 (only one of which is shown). An upper extending arm 94and a lower extending arm 96 are integral with the cross arm90. The lower arm 96 has a tip 98 which-rides in a box cam slot 100 on the locking cam shaft 13. The upper arm 94 rides in an appropriate circumferential slot 102 on the selector unit 45. The box cam 100 has a cam rise 104 which acts on the contained tip 98 at the proper period during rotation of the locking cam shaft 13 to shift the selector unit 45 rightward by rocking cross arm 90 clockwise in response to tip 98 riding up the cam rise. It will be noted that the cam rise is approaching the tip 98 in Fig. 1. Rotation of the locking cam shaft causes the selector unit 45 to be swiftly shifted to the right and then back to the left to temporarily remove the projection 47 from beneath the contact lug 51-1. This shifting movement of the selector unit 45 is so timed as to occur just as the numeral wheels of the register are released by their respective cam lobes 80. Therefore if the same digit is selected in successive cycles, the components always angularly move 360 to successively assume the same digital display position, thus permitting the first order numeral wheel to advance and subsequently permitting its adjacent interordinal member to advance to thereby properly propagate the numbers.

Due to manufacturing considerations, all of the numeral wheels are identical and all of the interordinal members are identical; thus it will be observed that due to the thickness of the respective contact and stop lugs, a contact lug will, upon abutment with its respective stop lug, lag behind the stop lug. Such lagging, or precession, would build up from order to order if means were not provided to prevent it.

In the preferred embodiment disclosed such lagging is compensated for by permitting each numeral wheel or interordinal member to advance by an additional amount corresponding to the thickness of the stop lug. For this purpose there is a slight interval between the time that a cam lobe 80 releases its respective numeral wheel and the time that the cam lobe 82 contacts the interordinal member. Thus, the interordinal member follows the numeral wheel for a short interval to advance from its lag position to a full digital position before it is centralized by cam lobe 82. The cam lobes are also designed to similarly permit any numeral wheel to follow its interordinal wheel by the amount required to eliminate the above described lag.

The description of the invention has thus far been premised on manual introduction of digital values and single cyclic operation of clutch 11 by key 19. The mechanism is also adaptable to operate continuously and read out consecutive digital values from a computer or the like. To this end the clutch would be automatically operated for a number of consecutive cycles which would equal the number of digits or orders in the value to be read out.

The individual digits, it will be recalled, are each introduced during the cyclic interval when the numeral wheels are locked, therefore, during read-out operation, the individual digits would necessarily be introduced in descending denominational order, with the individual entries operable to adjust a device such as dial 31, and timed each cycle to occur while the numeral wheels are locked. In this manner, for example, a ten-order decimal value would be read out in ten continuous cycles of operation to a ten-order mechanical shift register.

Certain computer output devices require that the dial 31 or its equivalent be rotated from its previous setting to its new setting even though the same value is to be entered into the register. For example, if the dial 31 stands at a value of 3 and a second value of 3 is to be entered therein, the dial 31 is rotated 360 from its starting position back to its original position. For this purpose the projection 47 is pivotally mounted at 48 to permit the projection to move clockwise against the urgency of its spring 49 as the projection passes the contact lug 51-1 on the numeral wheel. This would occur slightly before 360 of rotation of the projection 47.

It will be apparent to those skilled in the art that multiorder value stored in the numeral wheel register may be translated into a serially generated pulse train of repre-* sentative electrical signals. This may be accomplished by repeatedly sensing the rotated position of the highest denominational order numeral wheel in the register. For example, in decimal operations the highest order numeral wheel would have a switch-closing projection which cooperates with one of ten switches to generate a representative pulse each time the numeral wheel is moved to a new position. It is apparent that the highest order numeral wheel displays successive decimal figures in the order of their introduction. Therefore, the selected numeral wheel will operate the ten switches in correspondence to the successive entries and thereby generate on ten discrete lines the pulse train representative of the decimal value in the numeral wheel register.

The numeral wheel register is cleared by entering a succession of zeros into the register.

The shift register may be used as a mechanically recirculating. mechanism in the following manner. Assume that an interordinal member is located to the left of the highest order numeral wheel of the register and that means are provided for selectively connecting and disconnecting this highest order member with the selecting unit 45. Further, assume that means are provided for selectively connecting and disconnecting the manually settable disc 31 from the selector unit 45. When the disc is disconnected and the highest ordinal member is connected to the member 45 and the clutch is continuously engaged, the value standing in the register will be continuously recirculated therethrough. Furthermore, assuming that the shift register is a ten-order register, then by effecting nine ordinal shifts through the recirculating mechanism, the value originally standing in the register will have been shifted one order to the right.

If the recirculated value is combined by means of a differential gear mechanism, with a value entered through the disc the shift register may be used as an accumulator register.

The invention claimed is:

l. A shift register comprising a drive shaft rotatable in one direction, a plurality of ordinally arranged numeral wheels frictionally mounted upon the drive shaft, means for adjusting a first numeralwheel to a discrete value representative position, respective detents for preventing rotation of the numeral wheels with the drive shaft, an interordinal member frictionally mounted on the drive shaft between each respective pair of numeral wheels, respective detents for preventing rotation of the interordinal members with the drive shaft, a respective stop lug fixed on each numeral wheel and each interordinal member, a respective contact lug fixed on each numeral wheel and each interordinal member, control means operable first to disable the detents of the interordinal members while the numeral wheel detents hold the numeral wheels in fixed position to permit the interordinal members to rotate with the drive shaft to the extent permitted by contact of a contact lug on the member with a stop lug on its adjacent numeral wheel, and operable second to disable the detents of the numeral wheels while the interordinal member detents hold the members in fixed position, to permit the numeral wheels to rotate with the drive shaft to the extent permitted by contact of their respective contact lugs with the stop lugs of their adjacent lower order interordinal members.

2. A mechanical shift register comprising a plurality of ordinally arranged numeral wheels each having a contact lug and a stop lug, a plurality of interordinal storing wheels one being located between each adjacent pair of numeral wheels, a contact lug and a stop lu-g being provided on each storing wheel, means for rotating a first numeral wheel in a predetermined direction to a selected value representative position, mechanism operable under control of the stop lug of said first numeral wheel and the contact lug of a respective storing wheel for rotating the storing wheel in the same direction to the same value representative position in whichthe first numeral; wheel stands, means subsequently operable under the'control of the; stop lug of the storing wheel and the and means-operable concurrently with the second numeral wheel,rotatingmeans forv rotating the first numeral wheel in the same, direction-to a second value representative position.

3. A. mechanical shift register comprising a plurality of ordinally, arranged. numeral wheels which are frictionally mounted on a shaft, a respective interordinal member frictionally mountedon the shaft between each adjacent pair of numeral wheels, means for alternately locking, the numeralwheels and the interordinal members against movement withsaid shaft, a lugon a first numeral wheel operable during rotation of the numeral wheel to contact; a selectively settable stoplug, a lug carried by the interordinal member operable upon rotation of said member tocontact a stop lug carried by the first numeral wheel, asecond' numeralwheel having a lug for contacting a stop lug. on theinterordinal member, and means operable in timed relationship with said locking means to move, the selectively settable stop lug out of the path of, rotation of said first numeral wheel contactlug.

4. A- recirculating shift register comprising a plurality of ordinally arranged numeral wheels with aninterordinal member located adjacenteach numeral wheel, adjustable means for controlling the rotation of a first numeral wheel to a discrete value representative position, mechanism operable under control of said numeral wheel for rotating the adjacent interordinal member to said discrete position, means operable under control of said interordinal member for rotating a second numeral wheel to said discrete position, mechanism operable under control of the second numeral wheel to rotate a second interordinal member to said discrete position, and means operable by said second interordinal member for adjusting said control means for the first numeral wheel.

5. In a shift register comprising a plurality of ordinally arranged numeral wheels, an interordinal member for each adjacent pair of numeral wheels, means tending to rotate the numeralwheels and the interordinal members ina common direction, means for alternately locking and releasing the numeral wheels, means for alternately locking and releasing the interordinal members, means for setting a first numeral wheel in a discrete value representative position, a stop lug on said first numeral wheel and operable when the numeral wheel is locked against rotation to contact a lug on the adjacent member and stop therotation thereof, a stop lug on the member and operablewhen the member is locked against rotation to contact a lug on a second numeral wheel and stop the rotation thereof, said stopping means for the numeral wheelsbeing operable as a group while the interordinal members are released as a group and vice versa with an interval of time being provided between the unlocking of one respective group and the locking of the other group to providea period of time during which both the numeral wheels and interordinal members are free to rotate.

6. A shift register comprising a plurality of N ordinally arranged value registering devices, cyclically operable means for shifting the respective values standing in the registering devices one order in a first direction for each cycle of operation, recirculating means connecting the endmost orders of the register and operable by said cyclically operable means to shift a value from one endmost order to the other endmost order, and mechanism for driving the cyclically operable means for X number of cyclesless than N to effect N-X ordinal shifts in a second direction.

7.- A mechanical shift register comprising a plurality of ordinally arrangednumeral-wheels frictionally mounted upon a drive shaft, a respective interordinal storage 8. member frictionally mounted on said shaft adjacent each. numeral, wheel and eachnumeral=wheel havinga stop, lug located inthe plane of; rotation of a. contact lug on; is respective storagemember, astop lug on each storage: member located in the plane of, rotation of: a contact-lug; on the respective adjacent ordinally higher numeralwheeh, a. cam shaft substantially parallel to the, drive shafeand, carrying. a locking cam for. each respective numeralwheel, and a locking cam for each respective interordinal mema. ber, a plurality of, mating surfaces on the numeralwheels, and members vfor cooperation with their respective cams,, said numeral wheel cams being diametrically opposed. to said member cams, and all of said cams describing an are less than whereby during each 180 rota: tion of, the cam shaft the numeral wheels andinterordinal members are unlocked to permit concurrent. rotation thereof.

8. A shift register as defined in claim 7 including means for rotating the drive shaft at a speed which is.

at least twice the speed of rotation of the. cam shaft. 9. A shift register as defined in claim 7 including-a selectively settable stop lug for cooperation with the,

stop, means operable to lock the first numeral Wheelin one often discrete positions, a stop lug in the numeral, Wheel, a storage member having a contact lug, means resiliently urging the contact lug of the storage member; in said predetermined direction into engagement with the numeral wheel stop, means operable to lock the storage member in one of ten discrete positions, a stop on said member, a second numeral wheel having a contact lug and resiliently urged into said predetermined direction into engagement with the stop on said member, a locking means for the second numeral wheel, control mechanism to cause alternate engagement of said numeral' wheel locking means and the storage member locking means, with a predetermined interval of. time between such alternate engagement which time interval is approximately equal to the time required for a numeral wheel or storage member to move a distance corresponding to the angular thickness of a stop lug on the storage wheel or member, respectively.

11. Ashift register comprising a plurality of ordinally arrangednumeral wheels frictionally mounted upon a drive shaftwhich is rotatable in a single direction, an interordinal member frictionally mounted on said shaft between each respective pair of numeral wheels, a stop carried by each numeral wheel and each member, a lug carried by each numeral wheel and each member-for cooperation with a stop on an adjacent member ornumeral wheel respectively, a second shaft parallel to the first shaft, a plurality of numeral wheel rotationpreventing locks and interordinal member rotation preventing locks carried on said second shaft, means'for rotating the second shaft to cause scquentiallockingof first the numeral wheels and then the interordinal members, and means for rotating the numeral wheeldrive shaft at a speed which is at least two times the speedof rotation of the second shaft to cause an interordinal member to be frictionally rotated to a predetermined value representative position under the control of a first locked numeral wheel and then to cause a second numeral wheel to be frictionally rotated to the samevalue representative position under the control of said interordinal member.

2,667,628.. Chaveneand Jan. 26, 19.54. 

